Spool for sewing machines



April .12, 1927. 8

F. F. BARTH v SPOOL FO-R SEWING MACHINES Filed Nov. 18. 1925 Fig.4 4 7 36 5 VIIIIIIIIIIIII flied-ri h, 7 b} ,Barth latentecl Apr. 12, 1927.

PATENT OFFICE.

FRIEDRICH FELIX EARTH, OF RADEBERG, GERMANY.

SPOOL FOR SEWING MACHINES.

Application filed November 18, 1925, Serial No. 69,784, and in GermanyMay 12, 1925.

The known arrangement of a friction and braking spring, on the bottom ofthe shuttle, to prevent the spool from turning too quickly and causingthe thread to unwind, with consequent trouble, has been found to answerits purpose in the case of central shuttles for sewing machines.According to the present invention, a spring for the same purpose isattached to the spool, in stead of to the shuttle, an arrangement whichrenders the advantages of such spring available, by using spoolsaccording to this invention, in the case also of shuttles in which abottom spring is not employed.

Moreover, should the spring be broken as the result of carelesshandling, the results are less inconvenient when the springs areattached to the spools themselves instead of to the shuttle.

One embodiment of the invention is illustrated in the accompanyingdrawing in which Figure l is an enlarged longitudinal section of thebobbin, along the line 11 of Figure 2;

Figure 2 is a plan, and

Figure 3 a side elevation.

A braking spring 3, in the form of a domed disc is attached to one ofthe flanges 2 of the spool l by rivets 42. The spring 3 is provided withan extension tongue 5 adapted to slide in an eyelet 6 stamped out of theflange 2. The domed spring 3 with a central aperture 7 exerts a moreuniform pressure than a flat spring projecting at an acute angle fromthe flange of the bobbin; though it is not intended that the use of aflat spring arranged in said manner should be excluded.

I claim:

1. In a spool for sewing machines the combination of a centralcylindrical portion flanges on same, and a flat spring fixed to theouter face of one of the said flanges and adapted to act in the axialdirection of the spool.

2. In a spool for sewing machines the combination of a centralcylindrical portion; flanges on same, and a flat spring fixed to theouter face of one of the flanges and adapted to act in the axialdirection of the spool, the said central cylindrical portion, flangesand spring being formed with a central passage extending through them.

3. In a spool for sewing machines the combination of a centralcylindrical portion; flanges on both ends of the same; a flat spring ofthe shape of a domed disk with a central hole on the upper face of theone .flange; means for fastening one side of the said spring at one sideof the last mentioned flange near its rim; means for guiding andsupporting the other side of the said spring on the other side of thesaid flange in such a way as to allow for flexing of the spring whilepreventing the full dis placement of the spring.

4. In a spool for sewing machines the combination of a hollow centralcylinder. flanges on the said cylinder, one of the said flanges beingformed with an eye, a spring mounted upon the said eyed flange andadapted to act in an axial direction, and a tongue upon the spring thesaid tongue being adapted to engage with the eye in F FRIEDRICH FELIXEARTH.

